Fighting ignorance since 1973.(It's taking longer than we thought.)

Are guinea pigs ever used as guinea pigs?

October 12, 2001

Dear Cecil:

Are guinea pigs ever REALLY used as … guinea pigs? You hear about lab rats and mice, but I can't recall ever seeing pictures of guinea pigs running mazes, being made to smoke cigarettes through a rubber tube, and so on while guys in white coats take notes. All I know is nobody's coming near MY guinea pig with any experimental substances.

Scott M., west Los Angeles

Illustration by Slug Signorino

Cecil replies:

We looked into this and found definite pluses and minuses to being a guinea pig.

Plus. While guinea pigs are sometimes used as guinea pigs — that is, as experimental subjects — this is comparatively rare. Ken Boschert, a veterinarian with Washington University’s division of comparative medicine and the operator of a Web site called Net Vet (netvet.wustl.edu/), estimates that 99 percent of experimental animals nowadays are rats and mice, which are small, cheap to feed, and reproduce quickly. More important, rats and mice are easier to manipulate genetically and can be made to model a greater range of human conditions than guinea pigs.

Minus. When guinea pigs do wind up in the lab, it ain’t pretty. A page on Dr. Boschert’s site reports that one use of guinea pigs is in the study of anaphylaxis (hypersensitivity to a substance following initial contact): “Sensitized guinea pig develops acute shock, respiratory collapse and death within 2-5 minutes upon later re-exposure to the antigen.”

Plus. Animal researchers in Peru are thinking about breeding “supermale” guinea pigs. “One enclosure can be used for breeding — a single male services a group of seven or eight females,” one on-line site reports. This moved little Ed to exclaim, “Now I have a goal for when I’m reincarnated!” Ever the adolescent.

Minus.The reason the researchers want to breed supermales is to increase guinea pig production — in Peru people eat guinea pigs for dinner. According to the International Development Research Centre (www.idrc.ca/adventure/guipigs.html), (link defunct) “In the cathedral of the city of Cuzco, the ‘navel’ of the Inca Empire, hangs a huge painting of the Last Supper. Surrounded by his 12 apostles, Jesus Christ sits at the table with a well roasted guinea pig in front of him which he is sharing with his guests.”

Plus. If you’re going to get eaten, you might as well get eaten by the Son of God.

One doesn’t wish to deprecate the scientific value of guinea pigs, which among other advantages have an immune system similar to ours and, like us, don’t synthesize their own vitamin C. (See netvet.wustl.edu/species/guinea/gpmo del.txt for a fuller discussion of the laboratory uses of guinea pigs.) Still, you have to wonder how guinea pigs became the proverbial test animal when they’re seldom used for that purpose. The earliest citation in the Oxford English Dictionary for guinea pig in the sense of experimental subject is from George Bernard Shaw in 1913: “The folly . . . which sees in the child nothing more than the vivisector sees in a guinea pig: something to experiment on.” Animal experiments in Shaw’s day were much less sophisticated than they are now, and one supposes guinea pigs comprised a larger portion of the experimental animal population. Or possibly Shaw just thought “guinea pig” sounded more genteel than “lab rat.”

We’re not even sure why guinea pigs are called guinea pigs. They don’t come from Guinea, which of course is in Africa; the guinea pig (Cavia porcellus, also known as the cavy) originated in South America. Some think Guinea was confused with the Guiana region, which is in South America, but this notion is generally discounted. One plausible theory is that guinea pigs were shipped back to Europe in Guineamen — that is, slave-trading vessels, which, having off-loaded their human cargo in the New World, needed paying freight for the long ride home.